Reference no: EM134354

Question 1. Determine the area of the shaded region (z=0.32). The graph depicts thestandard normal distribution with mean 0 and standard deviation 1.

Question 2. Evaluate the area of the shaded region (z=0.99). The graph depicts the standard normal distribution of bone density scores with mean 0 and standard deviation 1.

Question 3. Determine the area of the shaded region. (z=0.82 , z=1.21)The graph depicts the standard normal distribution of bone density scores with mean 0 and standard deviation1.

Question 4. Evaluate the indicated z score. (0.2358 shaded curve, z is on the vertical  line, 0 not shaded on bottom graph  )The graph depicts the standard normal distribution with mean 0 and standard deviation 1.

Question 5. Determine the indicated z score. The graph depicts the standard normal distribution with mean 0 and standard deviation1.( 0 bottom shaded,z on vertical line and 0.8051 shaded curve)

Question 6. Compute the indicated z score. The graph depicts the standard normal distribution with mean 0 and standard deviation 1. (0 bottom of graph, z on vertical line, 0.1230 shaded on graph)

Question 7. The test scores are normally distributed with a mean 0 and a standard deviation of 1. Find the probability that a given score is less than -1.65. The probability is?

Question 8. Evaluate the indicated area under the curve of the standard normal distribution, then convert it to a percentage and fill in the blank. About what % of the area is between z=1.9 and z= 1.9(or within 1.9 standard deviations of the mean).

Question 9. A survey found that women's heights are normally distributed with mean 62.8 in. and standard deviation 2.9 in. The survey also found that men's heights are normally distributed with a mean 68.3 in. and standard deviation 2.8. Most of the live characters at an amusement park have height requirements with a minimum of 4ft 9in. and a maximum of 6ft 2 in.

 Compute the percentage of women who meet the heightrequirement?

 Compute the percentage of men that meet the height requirement?

If the height requirements are changed to exclude only the tallest 5% of men and the shortest 5% of women, what are the new height requirements? The new height requirements are at least how many in. and  at most how many in.?

Question 10. A genetics experiment involves a population of fruit flies consisting of 2 males named Christopher and Donald and 2 females named Fergie and Emily. Suppose that two fruit flies are randomly selected with replacement. After listing the possible samples and finding the proportion of males in each sample, use a table to explain the sampling distribution of the proportion of males.

Proportion of males          Probability

     0                                          ?                                                                                                                                                      

    0.5                                        ?

     1                                          ?

Question 11.  Suppose that women's heights are normally distributed with a mean given by u=62.7 in., and astandard  deviation given by o~= 1.8 in. a.) If 1 woman is randomly selected, find the probability that her height is less than 63in. b.)If 36 women are randomly selected, evaluate the probability that they have a mean height less than 63 in.

Question 12. Consider that a women's heights are normally distributed with a mean given by u=64.4in., and a standard deviation given by o~=2.5 in., If 1 woman is randomly selected, Evaluate the probability that her height is between 63.9 in. and 64.9 in.

Question 13. Evaluate the critical value z a/2 that corresponds to a=0.17

Question 14. A research institute poll asked respondents if they felt vulnerable to identify theft. In the poll, n=1007 and x=564 who said yes. Use a 90% confidence level.

A)     Determine the best point estimate of the population proportion p.

B)      Identify the value of the margin of error E

C)      Prepare the confidence interval

D)     Write a statement that correctly interprets the confidence interval

Question 15. A research institute poll asked respondents if they acted to annoy a bad driver. In the poll n=2333, and x=1112 who said that they honked. Use a 95% confidence level.

A) Determine the best point estimate of the population proportion p                                                     

B)Identify the value of the margin of error E

C)prepare the confidence interval

D)Write a statement that correctly interprets the confidence interval

Question 16. A clinical trialtests a method designed to increase the probability of conceiving a girl. In the study 300 babies were born, and 255 of them were girls. Use the sample data to prepare a 99% confidence interval estimate of the percentage of girls born. Based on the result, does the method appear to be effective ?

Question 17. In a poll of 503 human resource professionals, 54.3% said that body piercings and tattoos were big grooming red flags.

A) Among the 503 human resource professionals who were surveyed, how many of them said that body piercings and tattoos were big grooming red flags?

B) Prepare a 99% confidence interval estimate of the proportion of all human resource professionals believing that body piercings and tattoos are big grooming red flags

C) Repeat part (b) using a confidence level of 80% and rounding to three decimal places

D) Compare the confidence intervals from parts (b) and (c) and check the interval that is wider. Why is it wider?

Question 18. Use the given data to find the minimum sample size needed to estimate a population proportion or percentage. Margin of error 0.06; confidence level 95%; p and q unknown.  N=?(round up to the  nearest integer)

Question 19. Many states are carefully considering steps that would help them collect sales taxes on items purchased through the Internet. How many randomly selected sales transactions must be surveyed to evaluate the percentage that transpired over the internet? Suppose that we want to be 90% confident that the sample percentage is within six percentage points of the true population percentage for all sales transactions.

Question 20. Use the given data to evaluate the minimum sample size required to estimate a population proportion or percentage. Margin of error: five percentage points;confidence level 95% ;from a prior study ^p is estimated by the decimal equivalent of 32%. N=? (round to the nearest integer)

Question 21. Evaluate the sample size, n, needed to estimate the percentage of adults who have consulted fortune tellers. Use a 0.02 margin of error, use a confidence level of 95%, and use results from a prior poll suggesting that 14% of adults have consulted fortune tellers. N=? (round to the nearest integer)

Question 22.   A researcher wishes to estimate the proportion of adults who have high speed internet access. What size sample should be obtained if she wishes the estimate to be within 0.02 with 90% confidence if A) she uses a previous estimate of 0.34?   B)she does not use any prior estimates?

Question 23.   A data set includes 106 body temperatures of healthy adult humans for which x =98.7 degrees Fahrenheit and s=0.63 degrees Fahrenheit. 

A) Evaluate best point estimate of the mean body temperature of all healthy humans?

B) Using the sample statistics, prepare a 99% confidence interval estimate of the mean body temperature of all healthy humans. Do the confidence interval limits contain 98.6 degree Fahrenheit? What does the sample suggest about the use of 98.6 degrees Fahrenheit  as the mean of body temp.?

Question 24. An IQ test is designed so that the mean is 100 and the standard deviation is 25 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 90% confidence that the sample mean is 3 IQ points of the true mean. Assume that O'=25 and determine the required sample size using technology. Then determine if this is a reasonable sample size for a real world calculation.

Question 25. In order to estimate the mean  amount of time computer users spend on the internet each month, how many computer users must be surveyed in order to be 90% confident that your sample mean is within 10 min. of the population mean? Assume that the standard deviation of the population of monthly  time spent on the internet is 206 min. What is a major obstacle to getting a good estimate of the population mean? Use technology to find the estimated minimum required sample size

 A) The minimum sample size required is ? Computer users

 B) List a major obstacle to getting a good estimate of the population mean

Question 26. Randomly selected students, participated in an experiment to test their ability to determine when on minute (or sixty seconds) has passed. Forty students yielded a sample mean of 59.1 seconds. Assuming that o'=11.1 seconds, construct and interpret a 90% confidence interval estimate of the population mean of all students. What is the 90% confidence interval for the population mean u?           (? < u <? )

Question 27. A study of the ages of motorcyclists killed in crashes involves the random selection or 144 drivers with a mean of 33.33 years. Assumingthat o'=8.2 years, construct and interpret a 90% confidence interval estimate of the mean age of all motorcyclists killed in crashes. What is the 90% confidence interval for the population mean u?

Question 28. Use the given confidence level and sample data to find a confidence interval for the population standard deviation o'. Assume that a simple random sample has been selected from a population that has a normal distribution. Salaries of college graduates who took a poetry course in college 98% confidence; n=41, x=$61,600, s=$18,101. (? <o' < ?)

Question 29. A simple random sample from a population with a normal distribution of 107 body temperatures has x=98.90 degrees F and s=0.64 degrees F.  Construct an 80% confidence interval estimate of the standard deviation of body temp. of all healthy humans. Is it safe to conclude that the population standard deviation is less than 1.80 degrees F?  (? degrees F < o' <  ? degrees F)

Question 30. The claim is that the proportion of adults who smoked a cigarette in the past week is less than 0.35, and the sample statistics include n=1055 subjects with 390 saying that they smoked a cigarette in the past week. Find the value of the test statistic?

Question 31. The claim is that the white blood cell countsof adult females are normally distributed with a standard deviation equal to 2.45. A random sample of 40 adult females has white blood cell counts with a mean of 7.83 and a standard deviation of 3.69. Find the value of the test statistic?

Question 32. The claim is that the IQ scores of statistics professors are normally distributed, with a mean less than 125. A sample of 18 professors had a mean IQ score of 122 with a standard deviation of 6. Find the value of the test statistic?

Question 33. Assume  that the significance level is a=0.05. Use the given information to find the P-value and the critical value(s). The test statistic of z=1.17 is obtained when testing the claim that p>0.2.

Question 34. Assume that the significance level is a=0.1. Use the given information to find the P-value and the critical value(s).  The test statistic of z= -1.18 is obtained when testing the claim that p<0.3.

Question 35. A certain drug is used to treat asthma. In a clinical trial of the drug, 15 of 278 treated subjects experienced headaches (based on the data from the manufacturer). The accompanying calculator display shows results from a test of the claim that less than 8% of treated subjects experienced headaches. Use the normal distribution as an approximation to the binomial distribution and assume a 0.01 significance level to complete parts a through e.

1-PropZTest

Prop<0.08

z=0.866838133

p=0.1930154000

^p=0.0664451827

n=301

a)Is the test two tailed, left tailed, or right tailed

b) what is the test statistic

c)what is the p-value

d)what is the null hypothesis and what do you conclude about it?

e)what is the final conclusion?

Question 36. A survey of 1,558 randomly selected adults showed that a 509 of them have heard of a new electronic reader. The accompanying technology display results from a test of the claim that 37% of adults have heard of the new electronic reader. Use the normal distribution as an approximation to the binomial distribution, and assume a 0.05 significance level to complete parts a through e.

Sample proportion: 0.326701

Test statistic, z: -3.5399

Critical Z:  +-1.9600

P-Value:  0.0004

a)Is the test two tailed, left tailed, or right tailed

b) what is the test statistic

c) what is the p-value

d)what is the null hypothesis and what do you conclude about it?

e) what is the final conclusion?

Question 37. A genetic experiment involving peas yielded on sample of offspring consisting of 412 green peas and 158 yellow peas. Use a 0.01 significance level to test the claim that under the same circumstances, 26% of offspring peas will be yellow. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that address the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.

Question 38. In a recent poll of 755 randomly selected adults, 588 said that it is morally wrong to not report all  income on tax returns. Use a 0.05 significance level to test the claim that 75% of adults say that it is morally wrong to not report all income on tax returns. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that address the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.

Question 39. In a recent poll, 775 adults were asked to identify their favorite seat when they fly, and 507 of them chose a window seat. Use a 0.01 significance level to test the claim that the majority of adults prefer window seats when they fly.Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that address the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.

Question 40. In a study of pregnant women and their ability to correctly predict the sex of their baby, 59 of the pregnant women had 12 years of education or less, and 33.9% of them correctly predicted the sex of their baby. Use a 0.01 significance level to test theclaim that these women have no ability to predict the sex of their baby, and the results are not significantly different from those that would be expected with random guesses.Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that address the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.

Question 41. When testing gas pumps for accuracy, fuel quality enforcement specialists tested pumps and found that 1292 of them were not pumping accurately (within 3.3 oz when 5 gal is pumped), and 5673 pumps were accurate. Use a 0.01 significance level to test the claim of an industry representative that less than 20% of the pumps are inaccurate. Use the P-value method and use the normal distribution as an approximation to the binomial distribution. Identify the null hypothesis and alternative hypothesis? Identify the P-value?

Question 42. A survey of 61,647 people included several questions about office relationships. Of the respondents, 25.8% reported that bosses scream at employees. Use a 0.05 significance level to test the claim that more than ¼ of people say that bosses scream at employees. How is the conclusion affected after learning that the survey is an online survey in which internet users chose whether to respond?Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that address the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.

Question 43. Assume that a simple random sample has been selected and test the given claim. Use the P-Value method for testing hypotheses. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim. The ages of actresses when they won an acting award is summarized by the statistics n=77, x=35.8 years, and s=11.9 years. Use a 0.01 significance level to test the claim that the mean age of actresses when they win an acting award is 33 years.